Purpose: The optimal extent of lymph node dissection for early-stage colon cancer (CC) remains undefined. This study assessed the influence of the extent of lymph node dissection on overall survival (OS) in patients with pT2 CC.
Methods: We retrospectively examined data from the multi-institutional registry system of the Japanese Society for Cancer of the Colon and Rectum and used a propensity score matching method to balance potential confounders of lymph node dissection. We extracted 463 matched pairs from 1433 patients who underwent major resections for pT2 CC between 1995 and 2004.
Results: Lymph node metastasis was found in 301 (21.0%) of 1433 patients with pT2 CC. In this cohort, significant independent risk factors for lymph node metastasis were lymphatic invasion and venous invasion. Patients who underwent D3 or D2 lymph node dissection did not significantly differ in OS, either among the propensity score-matched cohort (estimated hazard ratio [HR] 0.85, 95% confidence interval [CI] 0.536-1.346, P = 0.484) or in the cohort as a whole (HR 0.720, 95% CI 0.492-1.052, P = 0.089).
Conclusions: For patients with pT2 CC, D3 lymph node dissection did not add to OS. D2 lymph node dissection may be adequate for pT2 CC.